Following each disturbing incident, Trump’s apologists tell us “that’s not who he is.” But his long campaign, and a long career in the public spotlight, tell us exactly who is is.

In 1996, a journalist (for Playboy, not surprisingly) who spent the weekend as Mr. Trump’s houseguest wrote of his impression of Trump the man: “Trump struck me as adolescent, hilariously ostentatious, arbitrary, unkind, profane, dishonest, loudly opinionated, and consistently wrong. He remains the most vain man I have ever met. And he was trying to make a good impression.” This strikes me as the most concise description of Trump the man that I have read, as perfectly calibrated today as when those words were written in 1996. Let’s deconstruct the elements:

·Adolescent. Arrested development is an essential feature of narcissistic personality disorder. It is no wonder that so many people watching him in action say he reminds them of the petulant bully in high school. In last night’s debate, he showed us that his argument style is stuck at grade school recess level (“You’re ugly.” “No, you’re ugly.”). When Mrs. Clinton commented that President Putin would “rather have a puppet as president of the United States” he responded: “No puppet, no puppet. You’re the puppet.”

·Hilariously ostentatious. Have a look online at pictures of Trump’s Fifth Avenue penthouse, with gilded everything and ridiculous thrones for “the King.”

·Arbitrary. The word means “based on random choice or personal whim, rather than any reason or system.” This precisely describes his fluid views, incoherent policies, and lack of any grounding ideological conviction.

·Unkind. The narcissist lacks empathy. He is incapable of genuine kindness and lacks respect for others, who he values only as means for satisfying some desire. This lack of empathy in turn permits . . .

·Profane. You’ve seen the video. His speech is crude and vulgar in public, and now we know it’s worse in private. The male narcissist, like Trump, typically has contempt for women while at the same time claiming to idealize them.

·Dishonest. As I argued in Trump and the truth, he is not so much a conscious liar as someone who regards as true the things that ought to be true in order to facilitate his desires or comply with his narrative of self. His disregard for reality is a crippling disability arising from his narcissistic disorder.

·Loudly opinionated. The narcissist is generally hostile to authority and expertise, regarding his own opinion as superior. In addition, he rarely is able to retreat from a view once expressed, which makes him . . .

·Consistently wrong. When you say whatever pops into your head and can rarely retreat from an opinion once expressed, you are consistently wrong. Consistently, not occasionally. PolitiFact rated 72% of Trump’s public remarks about factual circumstances as false. And it is all rooted in . . .

·Most vain man I have ever met. I hope you read the last post in which I let Mr. Trump speak for himself. It’s hard not to reach the same conclusion regarding vanity. But how vain, really? Professor of psychology Dan McAdams describes following:“When, in the summer of 1999, he stood up to offer remarks at his father’s funeral, Trump spoke mainly about himself. It was the toughest day of his own life, Trump began. He went on to talk about Fred Trump’s greatest achievement: raising a brilliant and renowned son. . . . Where others spoke of their memories of Fred Trump, [Donald] spoke of Fred Trump’s endorsement.”

The people who best understand how personality disorders translate into sociopathic behavior are alarmed. More than 2200 mental health professionals, both practicing and academic psychiatrists and psychologists have signed an on-line manifesto. They are united by the conviction that Mr. Trump suffers from an extreme case of narcissistic personality disorder. Because professional ethics do not allow psychiatrists and psychologists to diagnose metal health disorders in persons not their patients, the manifesto deals with Trump’s “public persona” and what they call “Trumpism.” These thousands of mental health professionals say that Trump has “fostered a cult of the Strong Man” who, among other things:

◦Appeals to fear and anger

◦Promises to solve our problems if we just trust in him

◦Reinvents history and has little concern for truth

◦Never apologizes or admits mistakes of consequence

◦Sees no need for rational persuasion

◦Subordinates women while claiming to idealize them

◦Disdains public institutions like the courts when they are not subservient, and

◦Incites and excuses public violence by supporters.

While Trump is a proto-typical narcissist, this is not his only personality defect. For example, noting his inability to stop speaking or tweeting, chronic inability to pay attention (people spending time with him report he fidgets “like a kindergartner who cannot sit still”), and shockingly deficient impulse control, others have diagnosed Trump as also having a severe case of ADHD. Professor McAdams, writing in The Atlantic, concluded, “Trump’s personality is certainly extreme by any standard.”

If ordinary people, even on casual acquaintance, easily perceive Mr. Trump as vain, immature, pompous, arbitrary, vulgar, dishonest, and uninformed, then how do we explain the dedication and enthusiasm of his core supporters? Part of it may be explained by the resonance of his nativist populist message. But this kind of adulation by the mob also is a common response to the narcissist, regardless of his message. One of the essential features of narcissism is that the narcissist simultaneously attracts and repels us. Professor Elizabeth Lunbeck framed the puzzle as follows: “Why is it that we are susceptible to narcissists’ charm even as we suffer their contempt?” Part of the answer is our attraction to what the Professor called their infectious, intoxicating self-confidence. And recent research, as reported in Psychology Today and Scientific American, suggests we often find selfish narcissistic jerks to be attractive: “The narcissist may initially ‘be hard to resist’ . . . seduc[ing] his victims into intoxicating submission . . . .”

But here is something in which we can take comfort. The same research concludes: “we can find consolation in the certainty that over time their appeal will fade.” Professor Lunbeck reminds us that, in the myth, Narcissus dies of what Francis Bacon called “rapturous admiration of himself.” Sociopathic narcissism is fatal. It never, ever, ends well for the narcissist.

Note on last night’s debate: This morning’s headline is Trump’s repeated refusal at the debate to say he will accept the results of the election. We’ve known this for a week. Six days ago, in my post A line crossed, I wrote: “He has moved from nascent demagogue and proto-fascist, to a full-blown enemy of constitutional democracy. He now tells his supporters that the ‘system is rigged,’ and if he loses it means the election will have been ‘stolen.’ This is an explicit and unprecedented repudiation of our democracy and its institutions. . . . I cannot see how he could possibly take the Presidential oath to ‘preserve, protect and defend the Constitution of the United States.’ Like all fascist demagogues, he rejects our laws and institutions, and offers in their place ‘I alone.’”

This is one of those moments when principle must prevail over expedience. History will judge harshly those who accommodate Trump’s repudiation of our electoral system. If the Republican Party does not contradict Trump within 24 hours, its very legitimacy will be at risk. They and to some extent the rest of us consistently have accommodated Trump’s repudiation of the norms of our political culture. We slid with him down a slippery slope, with the inevitable result.

One more thing. While there is no excuse for what he has done, there is an explanation. If you believe as I do that his personality defects are the main drivers of his behavior, then it was predictable, even inevitable. His core narrative is that he is a winner and his enemies are losers. Some losses simply can be denied (like his many business failures, where he generally just carries on claiming they were in fact a success). But when the loss cannot be denied (such as not receiving the Emmy or losing the election), the only possible way to reconcile the fact of loss with the deeper truth of his core “winner” narrative is to claim that the contest was rigged. So of course he couldn’t say that he would accept the election result as fair and honest. If he loses on November 8 he will go to his grave believing that the election was unfair, and that a vast conspiracy of powerful forces dishonestly conspired to rob him of the victory that otherwise would have been his. This is who Donald Trump is.